This invention relates generally to encryption/decryption of data, and to data carriers incorporating arrangements for encryption/decryption of data.
Electronic devices are commonly used to carry data (such as, for example, financial or personal data) which must be kept secure from unauthorised access. A typical method of preventing unauthorised access to data carried in such devices is by the use of a password.
A typical, known password scheme involves the use of the known Data Encryption Standard (DES) to encrypt/decrypt the password. In its steps the Data Encryption Standard algorithm requires data to be permuted in a predetermined manner.
The practical implementation of the Data Encryption Standard typically requires the presence of extra registers and/or additional processing steps to effect the required permutations.
It is an object of the present invention to provide an arrangement for encryption/decryption of data, and a data carrier incorporating same, in which the above disadvantages are overcome or at least alleviated.
In accordance with a first aspect of the invention there is provided an arrangement for encryption/decryption of data as claimed in claim 1.
In accordance with a second aspect of the invention there is provided an arrangement for encryption/decryption of data as claimed in claim 2.
In accordance with a third aspect of the invention there is provided a data carrier incorporating an arrangement for encryption/decryption of data as claimed in claim 6.